Race cars used in automobile racing are typically constructed such that only a minimal amount of clearance is maintained between the underside of the car and the surface of the roadway or track. This is done to lower the center of gravity of the vehicle to improve vehicle handling and resistance to rolling over, and to minimize the drag on the car due to the air passing underneath. Such race cars typically have very stiff suspension systems which do not allow the vehicle to travel as great a distance up and down nor side-to-side as a standard production car, thus allowing for a reduced ground clearance. However, one of the challenges encountered in lowering the race car closer to the race track is providing sufficient clearance for the vehicle exhaust system, which is one of the lowest hanging components of a typical car, including race cars.
This problem is particularly acute on cars which race on oval race tracks, such as stock cars. The exhaust pipes of stock cars typically exit toward one or both sides of the car so as to minimize the length of the exhaust pipes and the resulting exhaust gas back pressure which lowers engine power output and overall engine performance. As such, the minimum ground clearance of the exhaust system often occurs where the exhaust pipes cross under the longitudinally-extending main frame members of the chassis at the sides of the vehicle. Stock cars typically race on oval tracks in a counter-clockwise rotational direction with centrifugal force causing the body and chassis of the car to lean toward the outside of the turn, or toward the right or passenger side of the car. Thus, the ground clearance on the right side of the car is usually less than the left side during cornering. Moreover, banked tracks can also induce high downward loads to the suspension system of stock cars requiring additional ground clearance.